Metamorphism of dry snow

Dry snow metamorphism is the process whereby the structure of a snowpack changes due both to diffusion, leading to sintering of adjacent crystals, and to vapor pressure gradients, which produce vapor flow and the growth of large crystals. A series of laboratory experiments is being performed using both natural snow and laboratory-grown ice spheres under carefully-controlled conditions to elucidate the underlying physics of the effects of temperature, temperature gradients, impurities and overburden on the mechanisms of dry snow metamorphism. The microstructure of the snow as it undergoes metamorphism is being related to its mechanical properties. The physical mechanisms and observed microstructures will be used to inform modeling of the processes. This project is funded by the Army Research Office, Terrestrial Sciences.